Turbine systems are continuously being modified to increase efficiency and decrease cost. One method for increasing the efficiency of a turbine system includes increasing the operating temperature of the turbine system and/or reducing cooling flows. To increase the temperature or reduce cooling, the turbine system must be constructed of materials which can withstand such temperatures during continued use.
In addition to modifying component materials and coatings, one common method of increasing temperature capability of a turbine component includes the use of cooling features, such as cooling channels and cooling holes. The cooling channels/holes are often formed in metals and alloys used in high temperature regions of gas turbines. One current method of forming the cooling channels includes costly drilling, such as with a laser or waterjet. Another method of forming the cooling channels includes costly electrical discharge machining.
With drilling and electrical discharge machining, the cooling channels can be difficult or impossible to form, resulting in increased scrap, which aids in driving up costs. As an alternative, direct metal laser melting (DMLM) or other additive manufacturing techniques are being considered for the formation of the cooling channels and/or cooling holes. While additive manufacturing can provide increased control over the formation of cooling channels in horizontal builds, it is difficult to control the shape of cooling channels/holes in vertical builds using additive manufacturing. In particular, it is difficult to control the closing of the channel/hole when build direction vector is in the same plane as the cross section of the channel/hole.
An article and a method of forming an article that show one or more improvements in comparison to the prior art would be desirable in the art.